ImmunoSero

For serum VDRL, the slide is rotated at: * 100 rpm for 4 minutes 100 rpm for 8 minutes 180 rpm for 4 minutes 180 rpm for 6 minutes

180 rpm for 4 minutes SERUM VDRL The slide is rotated for 4 minutes on a rotator at 180 rpm. It is read microscopically to determine the presence of flocculation, or small clumps. The results are recorded as reactive (medium to large clumps), weakly reactive (small clumps), or nonreactive (no clumps or slight roughness).

Which CD4:CD8 ratio is most likely in a patient with acquired immunodeficiency syndrome (AIDS)? * 2:1 3:1 2:3 1:2

1:2 An inverted CD4:CD8 ratio (less than 1.0) is a common finding in an AIDS patient. The Centers for Disease Control and Prevention requires a CD4-positive (helper T) cell count of less than 200/μL or 14% in the absence of an AIDS-defining illness (e.g., Pneumocystis carinii pneumonia) in the case surveillance definition of AIDS.

Several large aggregates; some free erythrocytes; clear supernatant: * 1+ 2+ 3+ 4+

3+ Negative: No aggregates Mixed field: A few isolated aggregates; mostly free-floating cells; supernatant appears red Weak (±) Tiny aggregates barely visible macroscopically; many free erythrocytes; turbid and reddish supernatant 1+ A few small aggregates just visible macroscopically; many free erythrocytes; turbid and reddish supernatant 2+ Medium-sized aggregates; some free erythrocytes; clear supernatant 3+ Several large aggregates; some free erythrocytes; clear supernatant 4+ All erythrocytes are combined into one solid aggregate; clear supernatant.

The rapid plasma reagin (RPR) test is rotated at what speed for which length of time? * 200 RPM for 10 minutes 100 RPM for 8 minutes 180 RPM for 4 minutes 125 RPM for 2 minutes

100 RPM for 8 minutes

For RPR, the card is rotated at: * 100 rpm for 4 minutes 100 rpm for 8 minutes 180 rpm for 4 minutes 180 rpm for 8 minutes

100 rpm for 8 minutes

Skin pH keeps most microorganisms from growing: * 5.6 6.5 7.2 8.0

5.6 Skin at a pH of approximately 5.6 This acidic pH keeps most microorganisms from growing.

Serological testing provides the most practical and reliable means of confirming a measles diagnosis. Samples collected before ___ may yield false-negative results, and repeat testing on a later sample is recommended in that situation. * 72 hours 5 days 6 days 9 days

72 hours IgM antibodies become detectable 3 to 4 days after appearance of symptoms and persist for 8 to 12 weeks.

What temperature is used to achieve DNA denaturation to a single strand? * 74 °C 92 °C 94 °C 102 °C

94 °C DENATURATION: 94C ANNEALING: 50 to 58C or higher EXTENSION: 72C

Which autoantibodies are strongly associated with granulomatosis with polyangiitis (Wegener's granulomatosis)? * ANA ANCA AMA ASMA

ANCA ANCA: ANTINEUTROPHILIC CYTOPLASMIC ANTIBODY

Which of the following is a unique characteristic of adaptive immunity? * Ability to fight infection Ability to remember a prior exposure to a pathogen A similar response to all pathogens encountered Process of phagocytosis to destroy a pathogen

Ability to remember a prior exposure to a pathogen

Antinuclear antibodies (ANA) include: * Abs to DNA Abs to DNA, abs to nucleolar antigens Abs to DNA, abs to nucleolar antigens and abs to histone Abs to DNA, abs to nucleolar antigens, abs to histone and abs to nonhistone proteins

Abs to DNA, abs to nucleolar antigens, abs to histone and abs to nonhistone proteins ANAs can be divided into four groups to provide a systematic classification: antibodies to DNA, antibodies to histone, antibodies to nonhistone proteins, and antibodies to nucleolar antigens.

Suppose an individual develops antibodies in response to a streptococcal pharyngitis infection. This is an example of: * Active immunity Passive immunity Adaptive immunity Immunoprophylaxis

Active immunity

Serum tested positive for HBsAg and anti-HBc IgM. The patient most likely has which of the following? * Acute hepatitis C Chronic hepatitis B Acute hepatitis B Acute hepatitis A

Acute hepatitis B The most likely answer is acute hepatitis B because of the presence of IgM anti-HBc in combination with the hepatitis surface antigen. Typically the presence of IgM indicates the presence of an acute phase of a disease.

Which of the following is considered to be nonsuppurative complication of streptococcal infection? * Acute rheumatic fever Scarlet fever Impetigo Pharyngitis

Acute rheumatic fever

Initial force of attraction that exists between A SINGLE FAB SITE ON AN ANTIBODY MOLECULE AND A SINGLE EPITOPE OR DETERMINANT SITE on the corresponding antigen: * Affinity Avidity

Affinity

For which of the following tests is a lack of agglutination a positive reaction? * Hemagglutination Passive agglutination Reverse passive agglutination Agglutination inhibition

Agglutination inhibition

What is the main difference between agglutination and precipitation reactions? * Agglutination occurs between a soluble antigen and antibody Agglutination occurs when the antigen is particulate Precipitation occurs when the antigen is particulate Precipitation occurs when both antigen and antibody are particulate

Agglutination occurs when the antigen is particulate Precipitation reactions occur between soluble antigen and soluble antibody that produce a visible end result typically in the form of a visible line of precipitate. Agglutination reactions occur when the antigen is particulate or coated on a particulate such as latex beads.

Which test, other than serological markers, is most consistently elevated in viral hepatitis? * Antinuclear antibodies Alanine aminotransferase (ALT) Absolute lymphocyte count Lactate dehydrogenase

Alanine aminotransferase (ALT) ALT is a liver enzyme and may be increased in hepatic disease. Highest levels occur in acute viral hepatitis, reaching 20-50 times the upper limit of normal.

Risk factors for hepatitis C virus (HCV) include: * Illegal IV drug use Occupational exposure Multiple sexual partners All of the above

All of the above

Which of the following is characteristic of B cells? * Phagocytic Participate in antibody-dependent cellular cytotoxicity (ADCC) reactions Contain surface immunoglobulins Secrete the C5 component of complement

Contain surface immunoglobulins B cells carry surface immunoglobulins that react to a specific antigen. The antigen can then be internalized processed and presented to an appropriate T helper cell. B cells are not phagocytic, nor do they participate in antibody-dependent cellular cytotoxicity (ADCC) reactions. Complement proteins are secreted by hepatocytes.

False-positive nontreponemal tests for syphilis may occur because of which of the following? * Infectious mononucleosis Systemic lupus erythematosus Pregnancy All of these

All of these

HTLV-I and HTLV-II can be transmitted by: * Bloodborne (transfusion, IV drug abuse) Sexual contact (commonly from men to women) Mother-to-child (mainly through breastfeeding) All of these

All of these

Interferons (IFN) have been demonstrated to act as: * Immunomodulators Antiviral agents Antineoplastic agents All of these

All of these

An antigen that triggers a type I hypersensitivity response: * Hapten Histamine Allergen Oncogene

Allergen

A deficiency can result in premature emphysema, especially in individuals who smoke or who are exposed to a noxious occupational environment: * Alpha1-antitrypsin Ceruloplasmin Haptoglobin Fibrinogen

Alpha1-antitrypsin

Type I hypersensitivity is: * Associated with complement-mediated cell lysis Due to immune complex deposition Mediated by activated macrophages An immediate allergic reaction

An immediate allergic reaction Type I hypersensitivity reactions occur immediately after second exposure to an allergen. On the first, or primary, exposure, IgE specific to the allergen is produced. The IgE binds to Fc receptors on the surface of basophils and mast cells. Immune complexes and complement are not involved in the response.

Of the following diseases, which one has the HIGHEST RELATIVE RISK IN ASSOCIATION WITH AN HLA ANTIGEN? * Ankylosing spondylitis Dermatitis herpetiformis Juvenile diabetes Rheumatoid arthritis

Ankylosing spondylitis

A patient with joint swelling and pain tested negative for serum RF by both latex agglutination and ELISA methods. What other test would help establish a diagnosis of RA in this patient? * Anti-CCP ANA testing Flow cytometry Complement levels

Anti-CCP Antibodies to cyclic citrullinated peptide are often found in RF-negative patients with rheumatoid arthritis.

Diagnosis of group A streptococci (Streptococcus pyogenes) infection is indicated by the presence of: * Anti-protein A Anti-DNase B Anti-beta-toxin C-reactive protein

Anti-DNase B The serological diagnosis of group A streptococcal infection can be made by demonstrating anti-DNase B. The antistreptolysin O (ASO) assay can also be used; however, ASO response is poor in skin infections.

Which is the first antibody detected in serum after infection with hepatitis B virus (HBV)? * Anti-HBs Anti-HBc IgM Anti-HBe All are detectable at the same time

Anti-HBc IgM Antibody to the hepatitis B core antigen (anti-HBc) is the first detectable hepatitis B antibody. It persists in the serum for 1-2 years post-infection and is found in the serum of asymptomatic carriers of HBV.

The serum of an individual who received all doses of the hepatitis B vaccine should contain: * Anti-HBs Anti-HBe Anti-HBc All of the above

Anti-HBs

Which hepatitis antibody confers immunity against reinfection with hepatitis B virus? * Anti-HBc IgM Anti-HBc IgG Anti-HBe Anti-HBs

Anti-HBs

The specific diagnostic test for hepatitis C is: * Absence of anti-HAV and anti-HBsAg Increase in liver serum enzyme levels Detection of non-A, non-B antibodies Anti-HCV

Anti-HCV

Present in 70% of patients with lupus and are highly specific for the disease: * Anti-DNP Anti-RNP Anti-dsDNA Anti-CCP

Anti-dsDNA Antibodies to dsDNA are present in 70% of patients with lupus and are highly specific for the disease.

A 20-year-old woman made an appointment to see her physician because she was experiencing intermittent diarrhea. Laboratory testing revealed that she also had an iron deficiency anemia. To determine if the patient has CELIAC DISEASE, her doctor should order which of the following laboratory tests? * Anti-tTG Antigliadin Antigluten All of the above

Anti-tTG CELIAC DISEAS: ANTIBODIES TO TISSUE TRANSGLUTAMINASE (tTG)Currently, detection of IgA antibodies to tTG is the serological method ofchoice for initial testing

Which of the following would be considered a significant finding in Graves disease? * Increased TSH levels Antibody to TSH receptors Decreased T3 and T4 Antithyroglobulin antibody

Antibody to TSH receptors

In Grave's disease, one of the main autoantibodies is: * Anti-CCP Antibody to islet cells of pancreas Antibody to thyroid-stimulating hormone receptor Anti-dsDNA

Antibody to thyroid-stimulating hormone receptor Autoantibody to the thyroid-stimulating hormone receptor ultimately causes release of thyroid hormones and a hyperthyroid condition.

What substance is detected by the rapid plasma reagin (RPR) and Venereal Disease Research Laboratory (VDRL) tests for syphilis? * Cardiolipin Anticardiolipin antibody Anti-T. pallidum antibody Treponema pallidum

Anticardiolipin antibody Reagin is the name for a nontreponemal antibody that appears in the serum of syphilis-infected persons and is detected by the RPR and VDRL assays. Reagin reacts with cardiolipin, a lipid-rich extract of beef heart and other animal tissues.

In the enzyme-linked immunosorbent assay (ELISA), which of the following can be attached to a solid-phase support (e.g. polystyrene)? * Antigen anzyme Antibody and albumin Antigen and antibody Antigen and albumin

Antigen and antibody

The classical complement pathway is activated by: * Most viruses Antigen-antibody complexes Fungal cell walls All of the above

Antigen-antibody complexes

Which of the following best describes a HAPTEN? * Not able to react with antibody Antigenic only when coupled to a carrier Has multiple determinant sites A large chemically complex molecule

Antigenic only when coupled to a carrier

Which of the following serologic tests is commonly performed by an immunofluorescence method? * Anti-HBs Antinuclear antibody (ANA) Antistreptolysin O (ASO) C-reactive protein (CRP)

Antinuclear antibody (ANA) Testing for antinuclear antibodies (ANAs) is commonly performed by the immunofluorescence method—using fluorescein-conjugated antihuman antibody to detect patient antibody bound to nuclear components of test cells.

The SUBCLASSES of IgG differ mainly in: * Type of L chain Arrangement of disulfide bonds Ability to act as opsonins Molecular weight

Arrangement of disulfide bonds

The subclasses of IgG differ mainly in: * Type of light chain Arrangement of disulfide bonds Ability to act as opsonin Molecular weight

Arrangement of disulfide bonds

The type of immunity that follows the injection of an immunogen is termed: * Artificial active Natural active Artificial passive Innate

Artificial active Active immunity follows exposure to an antigen that stimulates the recipient to develop his or her own immune response. Vaccines are an example of artificial immunity in that the animal was exposed to the immunogen by the actions of a healthcare provider (unnatural).

The type of immunity that follows the injection of antibodies synthesized by another individual or animal is termed: * Artificial active Natural adaptive Artificial passive Natural passive

Artificial passive Artificial passive immunity results following the injection of antibody synthesized by another individual or animal. This type of immunity is only temporary but may be very important in providing "instant" protection from an infectious agent before the recipient would have time to actively synthesize antibody.

Loss of self-tolerance results in: * Autoimmune disease Graft-versus-host disease Immunodeficiency Tumors

Autoimmune disease The immune system recognizes host cells as self and is tolerant to antigens on those cells. The loss of tolerance will result in an autoimmune disease in which the immune system mounts an immune response against self cells.Graft-versus-host disease occurs when a bone marrow graft is incompatible with the host tissue and attacks the host.

It represents the sum of all the attractive forces between an antigen and an antibody: * Affinity Avidity

Avidity

All are components of the second line of defense, except: * Macrophages Mast cells Neutrophils B cells

B cells SECOND LINE OF DEFENSE: Cellular 1. Mast cells 2. Neutrophils 3. Macrophages Humoral 1. Complement 2. Lysozyme 3. Interferon

Which is most likely a positive Western blot result for infection with HIV? * Band at p24 Band at gp60 Bands at p24 and p31 Bands at p24 and gp120

Bands at p24 and gp120 Criteria for determining a positive test result have been published by the Association of State and Territorial Public Health Laboratory Directors and CDC, the Consortium for Retrovirus Serology Standardization, the American Red Cross, and the FDA. According to these criteria, a result should be reported as positive if at least two of the following three bands are present: p24, gp41, and gp120/gp160.

Tissue mast cells resemble: * Basophil Eosinophil Monocyte Neutrophil

Basophil

IgE has the ability to activate: * B cells B cells and T cells Basophils and mast cells Eosinophils and neutrophils

Basophils and mast cells IgE is best known for its very low concentration in serum and the fact that it has the ability to activate mast cells and basophils.

A 1-year-old boy is seen for having many recurrent infections with Streptococcus pneumoniae. Laboratory tests revealed a normal quantity of T cells, but no B cells and no immunoglobulins were seen on electrophoresis. Which of the following would most likely be the cause? * Chronic granulotomatous disease Bruton's agammaglobulinemia DiGeorge's syndrome Wiskott-Aldrich syndrome

Bruton's agammaglobulinemia Bruton's agammaglobulinemia is typically seen in infancy. These patients present with frequent recurring infections, especially after protective maternal antibody is gone and normal levels of circulating T cells. The syndrome is a genetic B cell enzyme deficiency in which the B cells fail to differentiate and mature to antibody-producing plasma cells.

A patient with hereditary angiodema has which of the following deficiencies? * C5-9 Phagocytic cell function Mature B cells C1 Inhibitor

C1 Inhibitor Hereditary angioedema is characterized by recurrent swelling. The condition is genetic or can be acquired and is the result of a deficiency of the complement protein C1 Inhibitor.

Mannose-binding protein in the lectin pathway is most similar to which classical pathway component? * C3b C1rs C1q C4

C1q

Mannose-binding lectin is similar to which component of the classical pathway? * C3 C2 C1q C5a

C1q Mannose-binding lectin (MBL) of the lectin pathway of complement activation is found in circulation complexed with proteinases. It is considered to be similar in structure to C1q of the classical pathway. The MBL-proteinase complex does not require antibody for complement activation.

What is the MOST COMMON complement component deficiency? * C1 C2 C3 C4

C2

The three complement activation pathways converge at the point of cleavage of complement component _____. * C3 C5 C7 C8

C3

What is MOST SERIOUS complement deficiency? * C1 C2 C3 C4

C3

Which complement component is present in the greatest quantity in plasma? * C2 C3 C4 C8

C3

Which of the following complement proteins is part of the membrane attack complex (MAC)? * Cl C3 C4 C5

C5 The membrane attack complex forms following the binding of C5 to a biologic membrane. The complex is formed by the sequential addition of C6, C7, C8, and C9. When C5-C8 complex with C9, a tubule is formed that bridges the cell membrane.

Which of the following complement components is a strong CHEMOTACTIC FACTOR as well as a strong ANAPHYLATOXIN? * C3a C3b C5a C4a

C5a

Which of the following is the best analyte to monitor for recurrence of ovarian cancer? * CA 15-3 CA 19-9 CA 125 CEA

CA 125

Which tumor marker is used to monitor patients with breast cancer for recurrence of disease? * CA 15-3 Estrogen receptor (ER) Cathepsin-D CA 50

CA 15-3

Which of the following tumor markers is used to monitor persons with breast cancer for RECURRENCE of disease? * Cathepsin-D CA 15-3 Retinoblastoma gene Estrogen receptor (ER)

CA 15-3 CA 15-3 shares the same antigenic determinant as CA 27.29. The markers are used to monitor treatment and recurrence of breast cancer.

Which receptor on T cells is responsible for rosetting with sheep red blood cells? * CD2 CD3 CD4 CD8

CD2

Antigen receptors on T lymphocytes bind HLA class II molecules with the help of which accessory molecule? * CD2 CD3 CD4 CD8

CD4

Antigen receptors on T lymphocytes bind HLA class II+ peptide complexes with the help of which accessory molecule? * CD2 CD3 CD4 CD8

CD4

As AIDS progresses, the quantity of _______ diminishes and the risk of opportunistic infection increases. * HIV antigen HIV antibody CD4+ T lymphocytes CD8+ T lymphocytes

CD4+ T lymphocytes

What criteria constitute the classification system for HIV infection? * CD4-positive T-cell count and clinical symptoms Clinical symptoms, condition, duration, and number of positive bands on Western blot Presence or absence of lymphadenopathy Positive bands on Western blot and CD8-positive T-cell count

CD4-positive T-cell count and clinical symptoms The classification system for HIV infection is based upon a combination of CD4-positive T-cell count (helper T cells) and various categories of clinical symptoms. Classification is important in determining treatment options and the progression of the disease.

A positive ANA with the pattern of ANTI-CENTROMERE ANTIBODIES is most frequently seen in patients with: * Rheumatoid arthritis CREST syndrome Systemic lupus erythematosus Sjogren syndrome

CREST syndrome Most patients with CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly, telangiectasia) demonstrate anti-centromere antibody.

Increased up to 1000x in inflammation: * Alpha1-antitrypsin and CRP Ceruloplasmin and C3 CRP and serum amyloid A Fibrinogen and haptoglobin

CRP and serum amyloid A

Which specimen is the sample of choice to evaluate latent or tertiary syphilis? * Serum sample Chancre fluid CSF Joint fluid

CSF If neurosyphilis is present, cerebrospinal fluid serology will be positive and the CSF will display increased protein and pleocytosis characteristic of central nervous system infection.

C1 consists of three subunits: C1q, C1r and C1s, which are bound together by: * Magnesium Calcium Iron Chloride

Calcium C1 forms the recognition unit of the complement pathway. It consists of three subunits stabilized by calcium.

Rapid plasma reagin (RPR) antigen contain cardiolipin with: * 10% saline Lipoteichoic acid Charcoal particles Fluorescein isothiocyanate

Charcoal particles

The migration of cells in the direction of a chemical messenger: * Chemotaxis Diapedesis Endosmosis Phagocytosis

Chemotaxis

The HLA complex is located primarily on: * Chromosome 3 Chromosome 6 Chromosome 9 Chromosome 17

Chromosome 6

Which disease might be indicated by antibodies to smooth muscle? * Atrophic gastritis Chronic active hepatitis Myasthenia gravis Sjögren's syndrome

Chronic active hepatitis

A 3-year-old boy is seen by his physician because of many recent bacterial infections. Flow cytometery indicates normal levels of T and B cells. The nitroblue tetrazolium test for oxidative reduction is negative. The most likely cause is: * Wegener's syndrome Chronic granulomatous disease Bruton's agammaglobulinemia Diabetes mellitus

Chronic granulomatous disease Chronic granulomatous disease is an inherited disease that impairs the neutrophil's ability to kill certain bacteria. The neutrophils lack the enzyme nicotinamide adenine dinucleotide phosphate oxidase, easily demonstrated by the failure to reduce nitroblue tetrazolium or produce a blue end result. These patients have normal levels of lymphocytes.

If only anti-HBs is positive, which of the following can be ruled out? * Hepatitis B virus vaccination Distant past infection with hepatitis B virus Hepatitis B immune globulin (HBIG) injection Chronic hepatitis B virus infection

Chronic hepatitis B virus infection Persons with chronic HBV infection show a positive test result for anti-HBc (IgG or total) and HBsAg but not anti-HBs. Patients with active chronic hepatitis have not become immune to the virus.

HLA molecules A, B, and C belong to which MHC class? * Class I Class II Class III Class IV

Class I

Antigenic groups identified by different sets of antibodies reacting in a manner to certain standard cell lines best describes: * Cytokines Clusters of differentiation (CD) Neutrophilic granules Opsonins

Clusters of differentiation (CD)

Antigenic groups identified by different sets of antibodies reacting in a similar manner to certain standard cell lines best describes: * Cytokines Clusters of differentiation (CD) Neutrophilic granules Opsonins

Clusters of differentiation (CD)

False-negative test results in a laboratory test for HIV antibody may occur because of: * Heat inactivation of the serum before testing. Collection of the test sample before seroconversion. Interference by autoantibodies. Recent exposure to certain vaccines.

Collection of the test sample before seroconversion.

The rapid plasma reagin assay for syphilis does not need to be read microscopically because the antigen is: * Cardiolipin Complexed with latex Complexed with charcoal Inactivated bacterial cells

Complexed with charcoal The rapid plasma reagin (RPR) and Venereal Disease Research Laboratory (VDRL) tests use a cardiolipin antigen. However, in the RPR test, charcoal particles are included with the antigen. When antibody in the patient sample combines with the antigen, the charcoal is trapped in the immune complex, allowing the reaction to be read macroscopically.

Antibody ALLOTYPE is determined by the: * Constant region of heavy chain Variable regions of heavy and light chains Constant region of light chain Constant regions of heavy and light chains

Constant regions of heavy and light chains

The polymerase chain reaction (PCR) involves three processes. Select the order in which these occur. * Extension→Annealing→Denaturation Annealing→Denaturation→Extension Denaturation→Annealing→Extension Denaturation→Extension→Annealing

Denaturation→Annealing→Extension The PCR process results in identical copies of a piece of double-stranded DNA. The process involves three steps that are repeated to double the number of copies produced with each cycle. The first step is denaturation to separate the complementary strands. Annealing occurs when a primer binds upstream to the segment of interest on each strand, called the template. Extension involves the enzymatic addition of nucleotides to the primer to complete the new strand.

Which cell is the most potent phagocytic cell in the tissue? * Neutrophil Dendritic cell Eosinophil Basophil

Dendritic cell

Which cell is the most potent phagocytic cell in tissue? * Neutrophil Dendritic cell Eosinophil Basophil

Dendritic cell

Which of the following frequently functions as an antigen-presenting cell? * Dendritic cell Cytotoxic T lymphocyte Natural killer cell T helper cell

Dendritic cell Dendritic cells are considered the most effective APC in the body, as well as the most potent phagocytic cell.

Most efficient antigen-presenting cell (APC): * B cell T cell Dendritic cell Macrophage

Dendritic cell Dendritic cells, however, are considered the most effective APC in the body, as well as the most potent phagocytic cell.

Most potent phagocytic cell: * Dendritic cell Eosinophil Macrophage Neutrophil

Dendritic cell Dendritic cells, however, are considered the most effective APC in the body, as well as the most potent phagocytic cell.

Considered the most effective antigen-presenting cells (APCs): * T cells Macrophages Neutrophils Dendritic cells

Dendritic cells Dendritic cells, however, are considered the most effective APC in the body, as well as the most potent phagocytic cell.

In a ____ immunofluorescent assay, ANTIBODY THAT IS CONJUGATED WITH A FLUORESCENT TAG is added directly to unknown antigen that is fixed to a microscope slide: * Direct immunofluorescent assay Indirect immunofluorescent assay Inhibition immunofluorescent assay

Direct immunofluorescent assay

The activity of natural killer (NK) cells: * Does not require previous exposure to an antigen Involves phagocytosis and killing of bacteria Requires interaction with cytotoxic T cells Requires interaction with B cells

Does not require previous exposure to an antigen The natural killer (NK) cells destroy target cells through an extracellular nonphagocytic mechanism. NK cells are part of the host's innate resistance and, therefore, do not need previous exposure to an antigen to be active.

Decreased maternal alpha fetoprotein levels are associated with: * Anencephaly Down syndrome Twins or multiple pregnancies Spina bifida

Down syndrome Causes of increased maternal serum alpha fetoprotein levels? 1. Open neural tube defects such as spina bifida and anencephaly can typically increase MSAFP by double or more. 2. Twins or multiple pregnancies can also increase the result. Cause of decreased maternal serum alpha fetoprotein levels: Down syndrome (trisomy 21) and Edwards syndrome (trisomy 18) can cause as much as a 25% decrease in MSAFP.

Anticoagulant for the direct AHG test (DAT): * ACD EDTA Heparin Oxalate

EDTA

Method of choice for diagnosis of congenital toxoplasmosis: * EIA IFA FAMA PCR

EIA Enzyme immunoassays (EIA) for IgM, IgG, or IgA and indirect fluorescent antibody (IFA) assays for IgG are available and should be performed when congenital toxoplasmosis is suspected. IFA testing has been widely used, but EIA is the method of choice, as it is more sensitive, less difficult to perform, and easier to interpret

The most commonly used method to detect VZV antibodies in the clinical laboratory: * Latex agglutination ELISA FAMA PCR

ELISA The most commonly used method to detect VZV antibodies in the clinical laboratory is the ELISA because it is automated, provides objective results, and does not require viral culture.

The most commonly used method to detect VZV antibodies in the clinical laboratory is: * ELISA PCR FAMA All of these

ELISA Varicella-Zoster virus (VZV) Antibodies ELISA - most common, easiest Automated, provides objective results, and does not require viral culture FAMA - reference method Considered to be the reference method for VZV antibody, it requires live, virus-infected cells and is not suitable for large-scale routine testing FAMA (fluorescent antibody to membrane antigen)

In the enzyme-linked immunosorbent assay (ELISA), the antihuman globulin is: * Fluorochrome-conjugated Auramine-conjugated Hormone-conjugated Enzyme-conjugated

Enzyme-conjugated

IgE recruits _____________ to the area to help destroy invading antigens that have penetrated IgA defenses: * B cells B cells and T cells Basophils and mast cells Eosinophils and neutrophils

Eosinophils and neutrophils IgE appears to be a nuisance antibody; however, it may serve a protective role by triggering an acute inflammatory reaction that recruits neutrophils and eosinophils to the area to help destroy invading antigens that have penetrated IgA defenses.

Select the term that describes the unique part of the antigen that is recognized by a corresponding antibody. * Immunogen Epitope Paratope Clone

Epitope

Most sensitive and reliable; reference method for VZV antibody: * Latex agglutination ELISA FAMA PCR

FAMA The most sensitive and reliable method of detecting VZV antibody is a fluorescent test called FAMA (fluorescent antibody to membrane antigen) that detects antibody to the envelope glycoproteins of the virus. While FAMA is considered to be the reference method for VZV antibody, it requires live, virus-infected cells and is not suitable for large-scale routine testing.

Which of the following is an example of a TREPONEMAL antigen test used for the diagnosis of syphilis? * CRP RPR VDRL FTA-ABS

FTA-ABS The fluorescent treponemal antibody absorbance (FTA-ABS) test is often used as a confirmatory test for syphilis. Treponema pallidum subsp. pallidum, the causative agent of syphilis, is the source of the antigen. The rapid plasma reagin (RPR) and Venereal Disease Research Laboratory (VDRL) are diagnostic tests for syphilis that use nontreponemal antigen.

The prozone phenomenon can result in a (an): * False-positive reaction False-negative reaction Enhanced agglutination Diminished antigen response

False-negative reaction

Rheumatoid factor is typically an IgM autoantibody with specificity for which of the following? * SS-B Double-stranded DNA Ribonucleoprotein Fc portion of IgG

Fc portion of IgG

Serves to promote aggregation of red blood cells, and increased levels contribute to an increased risk for developing coronary artery disease, especially in women: * Alpha1-antitrypsin Ceruloplasmin Haptoglobin Fibrinogen

Fibrinogen

The Venereal Disease Research Laboratory (VDRL) test for syphilis is classified as a(n): * Agglutination reaction Flocculation reaction Hemagglutination reaction Precipitation reaction

Flocculation reaction The cardiolipin antigen is particulate, not soluble, in the VDRL test. However, the particles are too small to make macroscopic agglutinates when combined with antibody. This type of reaction is called a flocculation reaction and needs to be read with low-power microscopy.

A biological false-positive reaction is LEAST likely with which test for syphilis? * VDRL Fluorescent T. pallidum antibody absorption test (FTA-ABS) RPR All are equally likely to detect a false-positive result

Fluorescent T. pallidum antibody absorption test (FTA-ABS) The FTA-ABS test is more specific for T. pallidum than nontreponemal tests such as the VDRL and RPR and would be least likely to detect a biological false-positive result. The FTA-ABS test uses heat-inactivated serum that has been absorbed with the Reiter strain of T. pallidum to remove nonspecific antibodies.

Microscope used for the Quantitative Buffy Coat (QBC) method for diagnosis of malaria: * Darkfield microscope Fluorescent microscope Phase contrast microscope Polarizing microscope

Fluorescent microscope

All of the following are characteristics of an effective immunogen except: * Internal complexity Large molecular weight Presence of numerous epitopes Found on host cells

Found on host cells

Which part of the radial immunodiffusion (RID) test system contains the antisera? * Center well Outer wells Gel Antisera may be added to any well

Gel In an RID test system, for example, one measuring hemopexin concentration, the gel would contain the antihemopexin. A standardized volume of serum containing the antigen is added to each well. Antigen diffuses from the well into the gel and forms a precipitin ring by reaction with antibody. At equivalence, the area of the ring is proportional to antigen concentration.

The BASIC STRUCTURE OF IMMUNOGLOBULINS was elucidated in the 1950s and 1960s by: * Georges Kohler and Cesar Milstein Gerald Edelman, Rodney Porter Susumu Tonegawa Rosalyn Yalow

Gerald Edelman, Rodney Porter

Color of the AHG reagent: * Red Yellow Blue Green

Green

Which surface marker is a reliable marker for the presence of high levels of hepatitis B virus (HBV) and a high degree of infectivity? * HBeAg HBsAg HBcAg Anti-HBsAg

HBeAg

The FIRST SEROLOGIC MARKER to appear in patients with acute hepatitis B virus infection is: * Anti-HBs Anti-HBc Anti-HBe HBsAg

HBsAg

Which hepatitis B marker is the best indicator of early acute infection? * HBsAg HBeAg Anti-HBc Anti-HBs

HBsAg Hepatitis B surface antigen (HBsAg) is the first marker to appear in hepatitis B virus infection. It is usually detected within 4 weeks of exposure (prior to the rise in transaminases) and persists for about 3 months after serum enzyme levels return to normal.

Which tumor marker is used to determine the usefulness of trastuzumab (Herceptin) therapy for breast cancer? * PR CEA HER-2/neu Myc

HER-2/neu Trastuzumab is an antibody to the HER-2/neu gene product, a tyrosine kinase receptor protein. HER- 2/neu is an oncogene that is overexpressed in some breast cancers. Overexpression is associated with a more aggressive clinical course but responds to treatment with trastuzumab, which blocks the attachment of growth factor to the receptor.

In monitoring an HIV-infected patient, which parameter may be expected to be the most sensitive indicator of the effectiveness of antiretroviral treatment? * HIV antibody titer CD4:CD8 ratio HIV viral load Absolute total T-cell count

HIV viral load The HIV viral load will rise or fall in response to treatment more quickly than any of the other listed parameters. The absolute CD4 count is also an indicator of treatment effectiveness and is used in resource-poor areas that might not have facilities for molecular testing available. Note that the absolute CD4 count is not one of the choices, however.

The fourth-generation ELISA tests for HIV detect: * HIV-1 and HIV-2 antigens HIV-1 and HIV-2 antibodies p24 antigen HIV-1 and HIV-2 antibodies and p24 antigen

HIV-1 and HIV-2 antibodies and p24 antigen FIRST GENERATION Solid-phase, indirect Anti-HIV1 SECOND GENERATION Indirect binding Anti-HIV1, anti-HIV2 THIRD GENERATION Sandwich technique Anti-HIV1, anti-HIV2 Simultaneously detecting HIV antibodies of different immunoglobulin classes, including IgM FOURTH GENERATION Detects anti-HIV1, anti-HIV2 and p24

Two cross-reacting antigen types of herpes simplex virus have been identified: * EBV and CMV HHV6 and HHV7 VZV and CMV HSV1 and HSV2

HSV1 and HSV2

Plays an important role in protecting the kidney from damage and in preventing the loss of iron by urinary excretion: * Alpha1-antitrypsin Ceruloplasmin Haptoglobin Fibrinogen

Haptoglobin

High titers of antimicrosomal antibodies are most often found in: * RA SLE Chronic active hepatitis Hashimoto's thyroiditis

Hashimoto's thyroiditis Hashimoto's thyroiditis is an autoimmune disorder that results in hypothyroidism. More than 80% of the patients with the disease have serum anti-thyroglobulin and anti-microsomal antibodies.

In the PCR cycle, how is denaturation accomplished? * Heat Alkali treatment Addition of sulfonylurea Formamide

Heat In PCR, the separation of dsDNA occurs by heating the sample. This breaks the double bonds between the base pairs and is reversible by lowering the temperature.

All of the following are true of IgE EXCEPT that it: * Fail to fix complement Heat stable Attaches to tissue mast cells Found in the serum of allergic persons

Heat stable IgE is the most heat-labile of all immunoglobulins; heating to 56°C for between 30 minutes and 3 hours results in conformational changes and loss of ability to bind to target cells.

All of the following hepatitis viruses are spread through blood or blood products except: * Hepatitis A Hepatitis B Hepatitis C Hepatitis D

Hepatitis A Hepatitis A is spread through the fecal-oral route and is the cause of infectious hepatitis. Hepatitis A virus has a shorter incubation period (2-7 weeks) than hepatitis B virus (1-6 months). Epidemics of hepatitis A virus can occur, especially when food and water become contaminated with raw sewage.Hepatitis E virus is also spread via the oral-fecal route and, like hepatitis A virus, has a short incubation period.

Which of the following tests is positive during the WINDOW PERIOD of infection with hepatitis B? * Hepatitis B surface antigen Hepatitis B surface antibody Hepatitis B core antibody Hepatitis C antibody

Hepatitis B core antibody

The Australia antigen is now called: * Dane particle Long-incubation hepatitis Hepatitis B surface antigen (HBsAg) Hepatitis B core antigen (HBcAg)

Hepatitis B surface antigen (HBsAg)

Acute-phase reactants are produced primarily by: * Endothelial cells Epithelial cells Fibroblasts Hepatocytes (liver parenchymal cells)

Hepatocytes (liver parenchymal cells)

Which type of cancer is associated with the highest level of AFP? * Hepatoma Ovarian cancer Testicular cancer Breast cancer

Hepatoma AFP is increased in all persons with yolk sac tumors and over 80% of those with hepatoma. Levels above 1000 ng/mL are diagnostic of hepatoma.

A lack of C1 INHIBITOR might result in which of the following conditions? * Paroxysmal nocturnal hemoglobinuria Hemolytic uremic syndrome Hereditary angioedema Increased bacterial infections

Hereditary angioedema

A lack of C1-INH might result in which of the following conditions? * Paroxysmal nocturnal hemoglobinuria Hemolytic uremic syndrome Hereditary angioedema Increased bacterial infections

Hereditary angioedema

The flexible portion of the heavy chain of an immunoglobulin molecule that is located between the first and second constant regions. * Heavy chain Hinge region Light chain Disulfide bonds

Hinge region

Gold standard for detecting rickettsial antibodies: * Weil-Felix test ELISA Immunoblot IFA and micro-IF

IFA and micro-IF IFA - indirect fluorescent assays Micro-IF - microimmunofluorescent assay The IFA test and the micro-IF are currently considered the gold standard for detecting rickettsial antibodies.

It has been used to treat hepatitis C and Kaposi's sarcoma, as well as certain leukemias and lymphomas: * TGF-alpha TGF-beta IFN-alpha IFN-beta

IFN-alpha IFN-α has been used to treat hepatitis C and Kaposi's sarcoma, as well as certain leukemias and lymphomas.

Efficacious in treating multiple sclerosis, although the exact mechanism of action remains unclear: * TGF-alpha TGF-beta IFN-alpha IFN-beta

IFN-beta IFN-β is efficacious in treating multiple sclerosis, although the exact mechanism of action remains unclear.

The immunoglobulin class typically found to be present in saliva, tears and other secretions is: * IgG IgA IgM IgD

IgA

Which antibody best protects mucosal surfaces? * IgA IgD IgG IgM

IgA

Recurrent, periodic fevers may be associated with increased production of which immunoglobulin? * IgG IgM IgD IgE

IgD Hyper IgD syndrome, also referred to as periodic fever syndrome, and Muckle-Wells syndrome. Hyper IgD is caused by a deficiency of mevalonate kinase, an enzyme involved in a sterol synthesis pathway. The syndrome has been seen primarily in northern European populations.

Measurement of serum levels of which of the following immunoglobulins can serve as a screening test for multiple allergies? * IgA IgE IgG IgM

IgE

Most heat-labile of all immunoglobulins: * IgA IgD IgE IgM

IgE

Which immunoglobulin cross links mast cells to release histamine? * IgG IgM IgA IgE

IgE

Which of the following immunoglobulins is present in the highest concentration in normal human serum? * IgM IgG IgA IgE

IgG

The major class of immunoglobulin found in adult human serum is: * IgA IgE IgG IgM

IgG Immunoglobulin G is Ihe predominant class of immunoglobulin found in serum. It accounts for approximately 80% of the total serum immunoglobulin. The normal range is 800-1600 mg/dL.

Primary antibody found in Helicobacter pylori infection: * IgA IgD IgG IgM

IgG Most serological tests in clinical use detect H. pylori-specific antibodies of the IgG class. Although IgM antibody is produced in H. pylori infections, testing for its presence lacks clinical value, since most infections have become chronic before diagnosis. Thus, IgG is the primary antibody found. IgA testing has a lower sensitivity and specificity than IgG testing, but it may increase sensitivity of detection when used in conjunction with IgG testing.

Diagnostic reagents useful for detecting antigen by the COAGGLUTINATION reaction may be prepared by binding antibody to killed staphylococcal cells via the Fc receptor of staphylococcal protein A. The class of antibody bound by this protein is: * IgA IgD IgG IgM

IgG Staphylococcal protein A binds only the IgG class (subclasses IgG1, IgG2, and IgG4) of immunoglobulin. Binding occurs via the Fc portion of the antibody molecule, leaving the Fab portion available to bind antigen in an immunologic assay.

Which immunoglobulin(s) help(s) initiate the classic complement pathway? * IgA and IgD IgM only IgG and IgM IgG only

IgG and IgM

Which antibody is best at agglutination and complement IgA IgG IgD IgM

IgM

Which antibody is best at agglutination and complement fixation? * IgA IgG IgD IgM

IgM

The serologically detectable antibody produced in rheumatoid arthritis (RA) is primarily of the class: * IgA IgE IgG IgM

IgM Rheumatoid factor (RF) is an immunoglobulin that reacts with antigenic determinants on an IgG molecule. Although they may be of several types, the one that is easily serologically detectable is IgM. This is because of the agglutination activity of the molecule. RF tests are commonly used in the diagnosis of rheumatoid arthritis.

Which class of immunoglobulin possesses 10 antigenic binding sites? * IgA IgD IgG IgM

IgM The IgM molecule is a pentamer that contains 10 binding sites. However, the actual valence falls to 5 with larger antigen molecules, probably because of steric restrictions. IgA, IgG, IgD, and IgE monomers each have two antigenic binding sites.

After exposure to antigen, the first antibodies that can be detected belong to the class: * IgA IgE IgG IgM

IgM The first B cells to respond to antigen differentiate into plasma cells that produce IgM antibody. Later in the immune response, stimulated B cells undergo a phenomenon called "class switching" and begin to produce antibodies of the IgG, IgA, and IgE classes. High concentration of IgM in patient serum is indicative of a recent infection.

Which immunoglobulin class(es) has (have) a J chain? * IgM IgE and IgD IgM and IgA IgG3 and IgA

IgM and IgA

Which of these are found on a mature B cell? * IgG and IgD IgM and IgD Alpha and beta chains CD 3

IgM and IgD

ACUTE HEPATITIS A is routinely diagnosed in symptomatic patients by demonstrating the: * HAV antigen IgM anti-HAV IgG anti-HAV

IgM anti-HAV

The immunoglobulin classes most commonly found on the surface of circulating B lymphocytes in the peripheral blood of normal persons are: * IgM, IgA IgM, IgG IgM, IgD IgM, IgE

IgM, IgD IgM and IgD are the classes of immunoglobulin that are found on most circulating B cells. They are in effect the B cell receptor.

Which immunologic mechanism is usually involved in BRONCHIAL ASTHMA? * Immediate hypersensitivity Immune complex Antibody mediated cytotoxicity Delayed hypersensitivity

Immediate hypersensitivity

Severe combined immunodeficiency(SCID) is an: * Immunodeficiency with decreased B cells and neutrophils Immunodeficiency with lymphocytopenia and eosinophilia Immunodeficiency with decreased or dysfunctional T and B cells Immunodeficiency with decreased lymphocytes and decreased complement concentration

Immunodeficiency with decreased or dysfunctional T and B cells SCID is defined as a condition in which adaptive immune responses (i.e., cell-mediated and humoral-mediated immune responses) do not occur because of a lack of T and B cell activity. A number of genetic defects can lead to this condition. Children born with SCID need to live in a sterile environment, and they have a short life expectancy.

What is the immunologic method utilized in the FLOW CYTOMETER? * Latex agglutination Immunofluorescence Enzyme linked immunoassay Radioimmunoassay

Immunofluorescence

Why might a COLONY STIMULATING FACTOR (CSF) be given to a cancer patient? * Stimulate activity of NK cells Increase production of certain types of leukocytes Decrease the production of TNF Increase production of mast cells

Increase production of certain types of leukocytes

Why might a colony stimulating factor be given to a cancer patient? * Stimulate activity of NK cells Increase production of certain types of leukocytes Decrease the production of TNF Increase production of mast cells

Increase production of certain types of leukocytes

A substrate is first exposed to a patient's serum, then after washing, ANTI-HUMAN IMMUNOGLOBULIN LABELED WITH A FLUOROCHROME is added. The procedure described is: * Fluorescent quenching Indirect fluorescence Direct fluorescence Fluorescence inhibition

Indirect fluorescence

The presence of C-reactive protein in a patient's serum indicates: * Inflammation Pneumococcal pneumonia Group A Strep infection Typhoid or paratyphoid

Inflammation

BLOCKING TEST in which an antigen is first exposed to unlabeled antibody and then to labeled antibody, and is finally washed and examined: * Direct immunofluorescent assay Indirect immunofluorescent assay Inhibition immunofluorescent assay

Inhibition immunofluorescent assay

The cells that Metchnikoff first observed are associated with which phenomenon? * Innate immunity Adaptive immunity Humoral immunity Specific immunity

Innate immunity

Cytokines produced by T cells and other cell lines that inhibit viral synthesis or act as immune regulators: * Integrins Interferons Complement Antibodies

Interferons

The most common means of HIV transmission worldwide is through: * Blood transfusions Intimate sexual contact. Sharing of needles in intravenous drug use. Transplacental passage of the virus.

Intimate sexual contact.

In FLUORESCENCE POLARIZATION IMMUNOASSAY (FPIA), the degree of fluorescence polarization is ____ proportional to concentration of the analyte. * Direct Inverse Variable No effect

Inverse

Serologic HLA testing uses a form of complement- dependent microlymphocytotoxicity (CDC) performed in 60-well or 72-well microtiter trays. Trays are usually read on: * Brightfield microscopes Darkfield microscopes Polarizing microscopes Inverted phase contrast microscopes

Inverted phase contrast microscopes Trays are usually read on inverted phase contrast microscopes. In the properly adjusted phase, cells that have not been injured appear small, bright, and refractile. Injured cells that have taken up eosin-Y or trypan blue owing to antibody and complement-mediated damage will flatten and appear large, dark, and nonrefractile.

A kidney transplant from one identical twin to another is an example of a(n): * Allograft Autograft Isograft Xenograft

Isograft Identical twins have the same genetic makeup. Grafts between them would be isografts or syngeneic grafts.

UNIQUE AMINO ACID SEQUENCE THAT IS COMMON TO ALL IMMUNOGLOBULIN MOLECULES of a given class in a given species: * Isotype Allotype Idiotype

Isotype

Characteristics of a bacterial capsule include which of the following? * It cannot be used for vaccine development It is composed of peptidoglycan It is an important mechanism for protecting a bacterium against ingestion by PMNs It is what causes bacteria to stain as gram-negative

It is an important mechanism for protecting a bacterium against ingestion by PMNs One of the most important features of a capsule is its role in blocking phagocytosis by WBCs.

Which of the following statements about the test for C-reactive protein (CRP) is true? * It correlates with neutrophil phagocytic function. It is an indicator of ongoing inflammation. It is diagnostic for rheumatic fever. Levels decrease during heart disease.

It is an indicator of ongoing inflammation. CRP is an acute-phase reactant. Although it is elevated in inflammation, its presence is not diagnostic for any one disease, such as rheumatic fever. It does not correlate with antibody levels or with neutrophil phagocytic function. CRP levels are sometimes elevated during heart disease.

In the anti-dsDNA procedure, the antigen most commonly utilized is: * Rat stomach liver Mouse kidney tissue Crithidia luciliae Toxoplasma gondii

Crithidia luciliae One particularly sensitive assay for ds-DNA is an immunofluorescent test using Crithidia luciliae, a hemoflagellate, as the substrate. This trypanosome has circular ds-DNA in the kinetoplast. A positive test is indicated by a brightly stained KINETOPLAST with patient serum and an antibody conjugate.

Most common cause of congenital infections: * Cytomegalovirus Rubella Syphilis Toxoplasmosis

Cytomegalovirus CMV is also the most common cause of congenital infections, occurring in approximately 1 percent of all neonates.

The characteristic laboratory finding in HIV infection is: * Decreased numbers of CD4 T cells. Decreased numbers of CD8 T cells. Decreased numbers of CD20 B cells. Decreased immunoglobulins.

Decreased numbers of CD4 T cells.

Which of the following is characteristic of DiGeorge syndrome? * Defective T lymphocyte production Depressed B cell development Suppressed intracellular killing by polymorphonuclear cells Suppressed complement levels

Defective T lymphocyte production Congenital thymic hypoplasia (DiGeorge syndrome)

What clinical manifestation would be seen in a patient with myeloperoxidase deficiency? * Defective T-cell function Inability to produce IgG Defective NK cell function Defective neutrophil function

Defective neutrophil function

Which of the following stages of infectious mononucleosis infection is characterized by ANTIBODY TO EPSTEIN-BARR NUCLEAR ANTIGEN (EBNA)? * Recent (acute) infection Past infection (convalescent) period Reactivation of latent infection Past infection, reactivation of latent infection

Past infection, reactivation of latent infection VCA - VIRAL CAPSID ANTIGEN EBNA - EBV NUCLEAR ANTIGEN EA - EARLY ANTIGEN CHARACTERISTICS DIAGNOSTIC PROFILE OF EBV SUSCEPTIBILITY If the patient is seronegative (lacks antibody to VCA) PRIMARY INFECTION Antibody (IgM) to VCA is present; EBNA is absent. PAST INFECTION Antibodies to VCA and EBNA are present. REACTIVATION If antibody to EBNA and increased antibodies to EA are present, patient may be experiencing reactivation.

It is considered the gold standard in testing for contact dermatitis: * RIST RAST Tuberculin test Patch test

Patch test The patch test is considered the gold standard in testing for contact dermatitis.

Innate immunity includes: * Anamnestic response Antibody production Cytotoxic T cell activity Phagocytosis by polymorphonuclear cells

Phagocytosis by polymorphonuclear cells Innate, or nonspecific, immunity refers to host defenses that are in general present at birth and do not require immunogen stimulation. Phagocytosis of bacteria by polymorphonuclear cells is an example.Cytotoxic T cell activity is part of the adaptive cell-mediated immune response, and antibody production is the mechanism of protection in the adaptive humoral-mediated immune response.

The structure formed by the fusion of cytoplasmic granules and the phagocytic vacuole during the process of phagocytosis: * Neutrophil Monocyte Phagosome Phagolysosome

Phagolysosome

A vacuole formed within a phagocytic cell as pseudopodia surround a particle during the process of phagocytosis: * Neutrophil Monocyte Phagosome Phagolysosome

Phagosome

The directions for a slide agglutination test instruct that after mixing the patient's serum and latex particles, the slide must be rotated for 2 minutes. What would happen if the slide were rotated for 10 minutes? * Possible false-positive result Possible false-negative result No effect Depends on the amount of antibody present in the sample

Possible false-positive result Failure to follow directions, as in this case where the reaction was allowed to proceed beyond the recommended time, may result in a false-positive reading. Drying on the slide may lead to a possible erroneous positive reading.

A SOLUBLE antigen and soluble antibody reacting to form an insoluble product describes: * Agglutination reactions Heterophile reactions Labeled reactions Precipitation reactions

Precipitation reactions Precipitation reactions involve both soluble antigens and antibodies.With agglutination reactions, one of the reactants is soluble and the other is insoluble. A reactant is made insoluble by combining with a carrier particle such as latex beads.

If an analyzer gets different results each time the same sample is tested, what type of problem does this represent? * Sensitivity Specificity Accuracy Precision

Precision

Anti-mitochondrial antibodies are strongly associated with which disease? * Autoimmune hepatitis Celiac disease Primary biliary cirrhosis Goodpasture's syndrome

Primary biliary cirrhosis

Antimitochondrial antibodies are strongly associated with which disease? * Autoimmune hepatitis Celiac disease Primary biliary cirrhosis Goodpasture's syndrome

Primary biliary cirrhosis

A biomarker that exhibits greater specificity than other proinflammatory markers in identifying patients with sepsis and can be used in the DIAGNOSIS OF BACTERIAL INFECTIONS: * Ceruloplasmin Cytokines CEA Procalcitonin

Procalcitonin Procalcitonin (PCT) is a biomarker that exhibits greater specificity than other proinflammatory markers (e.g., cytokines) in identifying patients with sepsis and can be used in the diagnosis of bacterial infections.

The main function of T cells in the immune response is to: * Produce cytokines that regulate both innate and adaptive immunity Produce antibodies Participate actively in phagocytosis Respond to target cells without prior exposure

Produce cytokines that regulate both innate and adaptive immunity

Acute phase reactants elevated up to 1000x in inflammation: * CRP and ceruloplasmin CRP and serum amyloid Ceruloplasmin and fibrinogen Ceruloplasmin and haptoglobin

Produced by the liver under the control of IL-6, CRP is a parameter of inflammatory activity.

In the process of phagocytosis, formation of hypochlorite and hydroxyl ions damage _______ irreversibly. * DNA RNA Carbohydrates Proteins

Proteins Formation of hypochlorite and hydroxyl ions damage PROTEINS irreversibly.

Which of the following is used to detect allergen specific IgE? * RIST RAST IEP CRP

RAST RIST - measures TOTAL IgE RAST - measures SPECIFIC IgE

Which technique represents a SINGLE-diffusion reaction? * Radial immunodiffusion Ouchterlony diffusion Immunoelectrophoresis Immunofixation electrophoresis

Radial immunodiffusion

Which technique represents a single-diffusion reaction? * Radial immunodiffusion Ouchterlony diffusion Immunoelectrophoresis Immunofixation electrophoresis

Radial immunodiffusion

Which would be most effective in measuring an individual complement component? * CH50 assay Radial immunodiffusion AH50 assay Lytic assay with liposome

Radial immunodiffusion The methods most frequently used to measure individual components include radial immunodiffusion (RID) and nephelometry

The antigenic component of the hepatitis B vaccine differs from those of many of the conventional vaccines in that it consists of a: * Live, attenuated virus Inactivated virus Cryptic antigen Recombinant antigen

Recombinant antigen Hepatitis A vaccine - inactivated vaccine Hepatitis B vaccine - recombinant antigen

A patient with a deficiency in complement component C7 would likely present with: * Recurrent Staphylococcal infections Recurrent Neisserial infections Recurrent Escherichia coli infections Recurrent Nocardia infections

Recurrent Neisserial infections

What would happen if the color reaction phase is prolonged in one tube or well of an ELISA test? * Result will be falsely decreased Result will be falsely increased Result will be unaffected Impossible to determine

Result will be falsely increased If the color reaction is not stopped within the time limits specified by the procedure, the enzyme will continue to act on the substrate, producing a falsely elevated test result.

What outcome results from improper washing of a tube or well after adding the enzyme-antibody conjugate in an ELISA system? * Result will be falsely decreased Result will be falsely increased Result will be unaffected Result is impossible to determine

Result will be falsely increased If unbound enzyme-conjugated anti-immunoglobulin is not washed away, it will catalyze conversion of substrate to colored product, yielding a falsely elevated result.

Anti-CCP (cyclic citrullinated proteins) is specifically associated with which autoimmune disease? * Rheumatoid arthritis Myasthenia gravis Autoimmune hepatitis Goodpasture's syndrome

Rheumatoid arthritis

The Weil-Felix test is used for the detection of which type of antibodies: * Salmonella Mycoplasma Rickettsial Viral

Rickettsial

Reactions involving IgG may need to be enhanced for which reason? * It is only active at 25°C. It may be too small to produce lattice formation. It has only one antigen-binding site. It is only able to produce visible precipitation reactions.

It may be too small to produce lattice formation.

The most frequent malignancy observed in AIDS patients is: * Pneumocystis jiroveci (P. carinii) Kaposi's sarcoma Toxoplasmosis Non-Hodgkin's lymphoma

Kaposi's sarcoma

Macrophages have specific names according to their tissue location. Macrophages in the liver are: * Alveolar macrophages Microglial cells Kupffer cells Histiocytes

Kupffer cells Histiocytes MACROPHAGES NOMENCLATURE IN DIFFERENT TISSUES CNS - Microglial cells Kidney - Mesangial cells Liver - Kupffer cells Lung - Alveolar macrophage Lymph node - Lymph node macrophage Spleen - Splenic macrophage

Which of the following serologic tests detects the polysaccharide capsule ANTIGEN in serum and CSF of patients with suspected infection with Cryptococcus neoformans? * Complement fixation India ink test Latex agglutination Hemagglutination test

Latex agglutination

In FLUORESCENCE POLARIZATION IMMUNOASSAY (FPIA), labeled antigens compete with unlabeled antigen in the patient sample for a limited number of antibody binding sites. The MORE antigen that is present in the patient sample: * Less fluorescence Greater fluorescence Less fluorescence polarization Greater fluorescence polarization

Less fluorescence polarization

Where do lymphocytes mainly come in contact with antigens? * Secondary lymphoid organs Bloodstream Bone marrow Thymus

Secondary lymphoid organs

In plasma, this acute phase reactant is associated with HDL cholesterol, and it is thought to play a role in metabolism of cholesterol: * CRP Ceruloplasmin Haptoglobin Serum amyloid

Serum amyloid

In plasma, it is associated with HDL cholesterol, and it is thought to play a role in metabolism of cholesterol: * Alpha1-antitrypsin Fibrinogen Mannose-binding lectin Serum amyloid A

Serum amyloid A

Type IV hypersensitivity reactions are responsible for all the following EXCEPT: * Contact sensitivity Elimination of tumor cells Rejection of foreign tissue grafts Serum sickness

Serum sickness

Carrier particles to which antigens are attached in Streptozyme testing: * Bentonite Charcoal Horse RBCs Sheep RBCs

Sheep RBCs The Streptozyme test is a slide agglutination screening test for the detection of antibodies to several streptococcal antigens. Sheep red blood cells are coated with streptolysin, streptokinase, hyaluronidase, DNase, and NADase so that antibodies to any of the streptococcal antigens can be detected.

Forward-angle light scatter is an indicator of cell: * Granularity Density Size Number

Size Scattered light in a forward direction is a measure of cell size, whereas the side scatter determines a cell's internal complexity, or granularity.

In ELISA, either antigen or antibody may be bound to ____ phase. * Liquid phase Semi-solid phase Solid phase

Solid phase A variety of solid-phase supports are used, including microtiter plates, nitrocellulose membranes, and magnetic latex beads.

The antigen used in the precipitation test is: * Soluble Insoluble Particulate Cellular

Soluble

In the chain of infection, a contaminated work area would serve as which of the following: * Source Method of transmission Host All of the above

Source

Which technique is used to detect DNA containing a specific base sequence by applying a labeled probe to DNA bands immobilized onto nitrocellulose paper following electrophoresis? * Southern blot Northern blot Western blot

Southern blot. SNOW DROP S - Southern Blot = D - DNA N - Northern Blot = R - RNA W - Western Blot = P - PROTEINS

Which of the following statements best characterizes adaptive immunity? * Relies on normally present body functions Response is similar for each exposure Specificity for each individual pathogen Involves only cellular immunity

Specificity for each individual pathogen

Marginal B cells remain in the: * Bone marrow Lymph nodes Spleen Peyer's patches

Spleen In the spleen, immature B cells develop into mature cells known as marginal zone B cells. These B cells remain in the spleen in order to respond quickly to any blood-borne pathogens they may come into contact with. Other immature B cells become follicular B cells, which are found in lymph nodes and other secondary organs.

A bacterial protein used to bind human immunoglobulins is: * HAV antibody, IgA type Escherichia coli protein C Staphylococcal protein A HAV antibody, IgG type

Staphylococcal protein A the Fc region of IgG and can be used to bind IgG in some laboratory assays.

Which technique involves probe amplification rather than target amplification? * Southern blot PCR Transcription-mediated amplification Ligase chain reaction

Ligase chain reaction

All the following are a function of T cells except: * Mediation of delayed-hypersensitivity reactions Mediation of cytolytic reactions Regulation of the immune response Synthesis of antibody

Synthesis of antibody

This disease was endemic in Haiti and was subsequently contracted and CARRIED TO EUROPE by COLUMBUS CREW: * Gonorrhea Syphilis Typhoid Hepatitis

Syphilis

Anti-dsDNA antibodies are associated with which of the following? * Syphilis CMV infection Systemic lupus erythematosus Hemolytic anemia

Systemic lupus erythematosus

One cause of a FALSE-POSITIVE VDRL test is: * Brucellosis Treponema pallidum infection Rocky Mountain spotted fever Systemic lupus erythematosus

Systemic lupus erythematosus Patients with connective tissue disorders such as systemic lupus erythematosus may show a false positive reaction in the VDRL test.Other causes of false positives include rheumatic fever, infectious mononucleosis, malaria, and pregnancy.

Which T cell expresses the CD8 marker and acts specifically to kill tumors or virally infected cells? * Helper T T suppressor T cytotoxic T inducer/suppressor

T cytotoxic

Of the circulating lymphocytes in peripheral blood, which are in the greatest percentages (60-80%)? * Natural killer cells Null lymphocytes B lymphocytes T lymphocytes

T lymphocytes

Contact dermatitis is mediated by: * B lymphocytes T lymphocytes Macrophages Polymorphonuclear cells

T lymphocytes Contact dermatitis is a delayed-type hypersensitivity reaction mediated by T cells.

A patient in septic shock caused by a gram-negative bacterial infection exhibits the following symptoms: high fever, very low blood pressure, and disseminated intravascular coagulation. Which cytokine is the most likely contributor to these symptoms? * IL-2 TNF IL-12 IL-7

TNF Tumor necrosis factor (TNF) secreted in response to gram-negative bacterial infections, causing a decrease in blood pressure, reduced tissue perfusion, and disseminated intravascular coagulation. The latter may lead to uncontrolled bleeding.

In Bruton disease, measurement of serum immunoglobulins would show: * Elevated levels of IgE Elevated levels of IgG Normal levels of IgG and IgM but reduced levels of IgA The absence of all immunoglobulins

The absence of all immunoglobulins Bruton disease is a congenital form of agammaglobulinemia. It is a sex-linked phenomenon that affects males. Because B cells are not produced, affected males have levels of IgA, IgD, IgE, and IgM undetectable by routine assays. IgG may be absent or present at very low levels.

CRP is produced by the: * Kidney Liver Bone marrow Thymus

Liver Produced by the liver under the control of IL-6, CRP is a parameter of inflammatory activity.

Father of Immunology: * Edward Jenner Louis Pasteur Gerald Edelman Paul Ehrlich

Louis Pasteur STEVENS, TURGEONLouis Pasteur is generally considered to be the Father of Immunology.

A patient report states the presence of serum antibodies to OspC. What disease does the patient most likely have? - IMPORTANT * Syphilis Strep throat Lyme disease Rubella

Lyme disease IMPORTANT!IgM antibody to OspC is an important early marker in the diagnosis of Lyme disease.

Where does the major portion of antibody production occur? * Peripheral blood Bone marrow Thymus Lymph node

Lymph node

A widely used HEMAGGLUTINATION test for detecting antibody to Treponema pallidum is: * MHA-TP test FTA-ABS test VDRL test RPR test

MHA-TP test

An RPR test done on a 19-year-old woman as part of a prenatal workup was negative but exhibited a rough appearance. What should the technologist do next? * Report the result out as negative. Do a VDRL test Send the sample for confirmatory testing. Make serial dilutions and do a titer.

Make serial dilutions and do a titer. Testing of sera from patients in the secondary stage is subject to false negatives because of the prozone phenomenon (antibody excess). In this case, a nonreactive pattern that is typically granular or rough in appearance is seen. If a prozone is suspected, serial twofold dilutions of the patient's sera should be made to obtain a titer.

What is the predominant type of antibody found in the serum of neonates born after full-term gestation? * Infant IgA Infant IgG Infant IgM Maternal IgG

Maternal IgG Antibody production is immunogen induced. Because the fetus develops in a sequestered site, it makes very little immunoglobulin. Maternal IgG crosses the placenta and is the primary antibody found in infant's circulation.

Which of the following can be attributed to IL-1? * Mediator of the innate immune response Differentiation of stem cells Halts growth of virally infected cells Stimulation of mast cells

Mediator of the innate immune response

A few isolated aggregates; mostly free-floating cells; supernatant appears red: * Negative Mixed-field Weak 1+

Mixed-field Negative: No aggregates Mixed field: A few isolated aggregates; mostly free-floating cells; supernatant appears red Weak (±) Tiny aggregates barely visible macroscopically; many free erythrocytes; turbid and reddish supernatant 1+ A few small aggregates just visible macroscopically; many free erythrocytes; turbid and reddish supernatant 2+ Medium-sized aggregates; some free erythrocytes; clear supernatant 3+ Several large aggregates; some free erythrocytes; clear supernatant 4+ All erythrocytes are combined into one solid aggregate; clear supernatant.

The best use of serum tumor markers is considered to be in: * Screening for cancer Initial diagnosis of cancer Monitoring patients undergoing cancer treatment Determining patient prognosis

Monitoring patients undergoing cancer treatment Tumor markers are best used to monitor patient response to therapy by performing serial measurements over time. If therapy is effective, the amount of tumor marker will decrease. Ineffective therapy and recurrence of cancer is indicated by an increase in the tumor marker level. Ideally, these increases would precede other signs of disease recurrence by several months.

All tissue macrophages arise from: * B lymphocytes Basophils Neutrophils Monocytes

Monocytes

In fluorescent antinuclear antibody testing, _______ or human epithelial HEp-2 cells are fixed to a slide and allowed to react with patient serum. * Rabbit kidney Rabbit spleen Mouse kidney Mouse spleen

Mouse kidney In fluorescent antinuclear antibody (FANA) testing, mouse kidney or human epithelial HEp-2 cells are fixed to a slide and allowed to react with patient serum.

In the production of hybridoma, plasma cells are harvested from: * Rabbit kidney Rabbit spleen Mouse liver Mouse spleen

Mouse spleen The production of hybridomas begins by immunizing a mouse with a certain antigen. After a time, the mouse's spleen cells are harvested. Spleen cells are combined with myeloma cells in the presence of polyethylene glycol (PEG), a surfactant. The PEG brings about fusion of plasma cells with myeloma cells, producing a hybridoma.

Cold agglutinins may develop after infection with: * Klebsiella pneumoniae Mycoplasma pneumoniae Streptococcus pneumoniae Haemophilus influenzae

Mycoplasma pneumoniae

Cells that express CD56 and/or CD16: * B cells T cells NK cells All of the above

NK cells Two subsets of NK cells exist—those that have a high level of CD56 and low or no CD16, and those with some CD56 and high levels of CD16.

A cell characterized by a nucleus with two to five lobes, a diameter of 10 to 15 μm, and a large number of neutral staining granules is identified as a(n): * Eosinophil Monocyte Basophil Neutrophil

Neutrophil

A cut on a person's finger becomes contaminated with the bacterium Staphylococcus aureus. The first response by the immune system consists of activity of: * B cells Monocytes Neutrophils T cells

Neutrophils The first response by the innate immune system consists of an influx of neutrophils into the tissue invaded by bacteria. Monocytes and macrophages, although they are phagocytic cells and part of the innate immune system, play only a minor role in the initial response to bacterial invasion.

Cells known to be actively phagocytic include: * Neutrophils, monocytes, basophils Monocytes, lymphocytes, neutrophils Neutrophils, eosinophils, monocytes Lymphocytes, eosinophils, monocytes

Neutrophils, eosinophils, monocytes

What is the interpretation when an Ouchterlony plate shows crossed lines between wells 1 and 2(antigen is placed in the center well and antisera in wells 1 and 2)? * No reaction between wells 1 and 2 Partial identity between wells 1 and 2 Nonidentity between wells 1 and 2 Identity between wells 1 and 2

Nonidentity between wells 1 and 2 Crossed lines indicate nonidentity between wells 1 and 2. The antibody from well 1 recognizes a different antigenic determinant than the antibody from well 2.

The antibody most frequently present in systemic lupus erythematosus is directed against: * Surface antigens of bone marrow stem cells Surface antigens of renal cells Nuclear antigen Myelin

Nuclear antigen Antinuclear antibody (ANA) is the most consistent feature of systemic lupus erythematosus (SLE).

Which tumor marker is associated with cancer of the urinary bladder? * CA 19-9 CA 72-4 Nuclear matrix protein Cathepsin-D

Nuclear matrix protein Nuclear matrix proteins (NMPs) are RNA-protein complexes. NMP-22 is shed into the urine in persons with bladder carcinoma and is about 25-fold higher than normal in this condition.

Which of the following statements regarding infection with hepatitis D virus is true? * Occurs in patients with HIV infection Does not progress to chronic hepatitis Occurs in patients with hepatitis B Is not spread through blood or sexual contact

Occurs in patients with hepatitis B Hepatitis D virus is an RNA virus that requires the surface antigen or envelope of the hepatitis B virus for entry into the hepatocyte. Consequently, hepatitis D virus can infect only patients who are coinfected with hepatitis B.

Which of the following positive antibody tests may be an indication of recent vaccination or early primary infection for rubella in a patient with no clinical symptoms? * Only IgG antibodies positive Only IgM antibodies positive Both IgG and IgM antibodies positive Fourfold rise in titer for IgG antibodies

Only IgM antibodies positive If only IgM antibodies are positive, this result indicates a recent vaccination or an early primary infection.

Which best explains the difference between immunogens and antigens? * Only antigens are large enough to be recognized by T cells Only immunogens can react with antibody Only immunogens can trigger an immune response Only antigens are recognized as foreign.

Only immunogens can trigger an immune response

The term for enhancement of phagocytosis by coating of foreign particles with serum proteins is * Opsonization Agglutination Solubilization Chemotaxis

Opsonization

Which of the following activities is associated with C3b? * Opsonization Anaphylaxis Vasoconstriction Chemotaxis

Opsonization

A woman with breast cancer is treated with a monoclonal antibody to HER2. This is an example of: * A cancer vaccine An immunotoxin Passive immunotherapy Active immunotherapy

Passive immunotherapy

Which of the following is true of NK cells? * They rely upon memory for antigen recognition They have the same CD groups as B cells They are found mainly in lymph nodes They kill target cells without prior exposure to them

They kill target cells without prior exposure to them

Which of the following statements is true of NK cells? * They rely upon memory for antigen recognition. They have the same CD groups as B cells. They are found mainly in lymph nodes. They kill target cells without prior exposure to them.

They kill target cells without prior exposure to them.

Which of the following is characteristic of variable domains of immunoglobulins? * They occur on both the H and L chains They represent the complement-binding site They are at the carboxy-terminal ends of the molecules They are found only on H chains

They occur on both the H and L chains

How do cytotoxic T cells kill target cells? * They produce antibodies that bind to the cell They engulf the cell by phagocytosis They stop protein synthesis in the target cell They produce granzymes that stimulate apoptosis

They produce granzymes that stimulate apoptosis CD8+ T cells are cytotoxic cells that are able to destroy cancer cells or virally infected host cells by producing PERFORINS and GRANZYMES.

How do cytotoxic T cells kill target cells? * 1 point They produce antibodies that bind to the cell. They engulf the cell by phagocytosis. They stop protein synthesis in the target cell. They produce granzymes that stimulate apoptosis.

They produce granzymes that stimulate apoptosis.

Hashimoto disease is an autoimmune disease primarily involving the: * Kidneys Liver Lungs Thyroid gland

Thyroid gland Hashimoto disease is a type of thyroiditis due to an autoimmune disease. Patients produce autoantibodies and T cells that respond to thyroid antigens. This results in inflammation and swelling of the thyroid gland (goiter). The autoantibody blocks the uptake of iodine, which results in a decrease in the production of thyroid hormones (hypothyroidism).

The serum titer in the ASO tube test is reported in: * Highest dilution that gives a positive result Lowest dilution that gives a negative result ASO units Todd or International Units

Todd or International Units

T in TORCH or STORCH stands for: * Trichinellosis Trichuriasis Toxoplasmosis None of the above

Toxoplasmosis

FTA-ABS is used to identify which of the following in the patient's serum? * Treponemal antibody Treponemes Reagin Cardiolipin

Treponemal antibody

An autoimmune disease causing destruction of pancreatic cells can result in: * Hashimoto disease Multiple sclerosis Myasthenia gravis Type 1 diabetes

Type 1 diabetes Destruction of the beta cells in the pancreas results in type 1 diabetes. An autoimmune response destroys the insulin-producing cells.

Elevated IgE levels are typically found in: * Type I hypersensitivity reactions Type II hypersensitivity reactions Type III hypersensitivity reactions Type IV hypersensitivity reactions

Type I hypersensitivity reactions Elevated IgE levels are found in type I hypersensitivity reactions. The antibody binds via the Fc portion of the molecule to Fc receptors on mast cells and basophils. When the attached antibody binds its specific allergen, the cell degranulates.

Incompatible blood transfusions are examples of: * Type I hypersensitivity reactions Type II hypersensitivity reactions Type III hypersensitivity reactions Type IV hypersensitivity reactions

Type II hypersensitivity reactions Incompatible blood transfusions are examples of a type II hypersensitivity reaction. These reactions are characterized as the antigen being a part of a cell. Antibody binds to the antigen, complement is activated, and the red blood cells are lysed.

Skin testing for exposure to tuberculosis is an example of which type of hypersensitivity? * Type I Type II Type III Type IV

Type IV Type IV hypersensitivity is the delayed-type hypersensitivity. Skin testing for tuberculosis causes a delayed-type hypersensitivity to intradermally injected antigens in individuals previously exposed to the organism.

Mantoux tuberculin test: * Type I hypersensitivity reaction Type II hypersensitivity reaction Type III hypersensitivity reaction Type IV hypersensitivity reaction

Type IV hypersensitivity reaction

What was one of the major contributions of Louis Pasteur to vaccine development? * Development of the smallpox vaccine Use of attenuated microorganisms in vaccines Inactivation of bacterial toxins for vaccines Discovery of recombinant vaccine antigens

Use of attenuated microorganisms in vaccines Louis Pasteur used the principle of attenuation, or weakened microorganisms, to produce vaccines against chicken cholera, anthrax, and rabies.

Which test is recommended for testing cerebrospinal fluid for detection of neurosyphilis? * RPR VDRL FTA-ABS Enzyme immunoassay

VDRL A positive VDRL test on spinal fluid is diagnostic of neurosyphilis because false positives are extremely rare.

Immunoglobulin IDIOTYPES are antibodies with variations in the domains of which of the following? * CH1 and CH2 VH and VL VH and CL CH1, CH2 and CH3

VH and VL Variations in the variable regions of the heavy and light chains of an immunoglobulin molecule define the idiotype.

Antibody IDIOTYPE is dictated by the: * Constant region of heavy chain Variable regions of heavy and light chains Constant region of light chain Constant regions of heavy and light chains

Variable regions of heavy and light chains

Tiny agglutinates turbid background: * 0 W+ 1+ 2+ 3+ 4+

W+ 0 No agglutination or hemolysis W+ Tiny agglutinates, turbid background 1+ Small agglutinates, turbid background 2+ Medium-sized agglutinates, clear background 3+ Several large agglutinates, clear background 4+ One solid agglutinate

Antibodies to which of the following viral antigens are usually the first to be detected in HIV infection? * gp120 gp160 gp41 p24

p24

Antibodies to which of the following viral antigens are usually the first to be detected in HIV infection? * gp120 gp160 gp41 p24

p24 In HIV-1 infection, antibodies to the gag proteins p24 and p55 appear relatively early after exposure to the virus, but tend to decrease or become undetectable as clinical symptoms of AIDS appear. Antibodies to the envelope proteins gp41, gp120, and gp160 appear slightly later but remain throughout all disease stages in an HIV-infected individual, making them a more reliable indicator of the presence of HIV.

Skin pH keeps most microorganisms from growing: * pH 5.6 pH 6.5 pH 7.2 pH 8.0

pH 5.6 Lactic acid in sweat, for instance, and fatty acids from sebaceous glands maintain the skin at a pH of approximately 5.6. This acidic pH keeps most microorganisms from growing.

Which is a distinguishing feature of a pre-B cell? * μ chains in the cytoplasm Complete IgM on the surface Presence of CD21 antigen Presence of CD25 antigen

μ chains in the cytoplasm

When soluble antigens diffuse in a gel that contains antibody, in which zone does OPTIMUM precipitation occur? * Prozone Zone of equivalence Postzone Prezone

Zone of equivalence

Papain digestion of an IgG molecule results in which of the following? * 2 Fab' and 1 Fc' fragment F(ab')2 and 1 Fc' fragment 2 Fab and 2 Fc fragments 2 Fab and 1 Fc fragment

2 Fab and 1 Fc fragment Papain digestion yields two Fab fragments and an Fc portion. Pepsin digestion yields an F(ab')2 fragment with all the antibody activity, as well as an Fc′ portion.

A single ASO titer is considered to be moderately elevated if the titer is at least ______ Todd units in an adult: * 160 200 240 320

240 A single ASO titer is considered to be moderately elevated if the titer is at least 240 Todd units in an adult and 320 Todd units in a child.

Treatment of IgG with papain results in how many fragments from each immunoglobulin molecule * 2 3 4 5

3

A single ASO titer is considered to be moderately elevated if the titer is at least ______ Todd units in a child. * 160 200 240 320

320 A single ASO titer is considered to be moderately elevated if the titer is at least 240 Todd units in an adult and 320 Todd units in a child.

A living donor is being sought for a child who requires a kidney transplant. The best odds of finding an MHC-compatible donor occur between the child and: * A sibling (brother or sister) An unrelated individual The child's father The child's mother

A sibling (brother or sister) Because the human leukocyte antigen (HLA) system is extremely polymorphic, the odds are greatly against finding an HLA-compatible donor in unrelated individuals. The genes coding for HLA antigens are inherited from one's parents and are expressed co-dominantly. Between an offspring and either parent, there is, statistically, a 25% chance of an HLA match. Between siblings, there is a 50% chance of an HLA match.

The only blood group system that affects clinical transplantation: * ABO Rh Kell Duffy

ABO The ABO system is the only blood group system that affects clinical transplantation.

An HLA specimen is collected in a tube containing: * ACD EDTA Silica Thrombin

ACD

Triggering substances for the alternative pathway: * Antigen-antibody complex Bacterial cell walls, especially those containing lipopolysaccharide; fungal cell walls; yeast; viruses; virally infected cells; tumor cell lines; and some parasites, especially trypanosomes Microorganisms with mannose or similar sugars in their cell wall All of the above

Bacterial cell walls, especially those containing lipopolysaccharide; fungal cell walls; yeast; viruses; virally infected cells; tumor cell lines; and some parasites, especially trypanosomes Triggering substances for the alternative pathway include bacterial cell walls, especially those containing lipopolysaccharide; fungal cell walls; yeast; viruses; virally infected cells; tumor cell lines; and some parasites, especially trypanosomes. All of these can serve as sites for binding the complex C3bBb, one of the end products of this pathway.

Serum amyloid A has been found to increase significantly more in: * Bacterial infections Fungal infections Parasitic infections Viral infections

Bacterial infections SERUM AMYLOID AIt has been found to increase significantly more in bacterial infections than in viral infections.

Current recommendations include the combined detection of mannan and anti-mannan antibodies for the specific identification of ______ species in serum samples. * Bordetella Mycobacterium Candida Cryptococcus

Candida Current recommendations include the combined detection of mannan and anti-mannan antibodies for the specific identification of Candida species in serum samples.

Antigen in the RPR test: * Anti-cardiolipin Cardiolipin Charcoal Reagin

Cardiolipin

What type of antigen is used in the RPR card test? * Live treponemal organisms Killed suspension of treponemal organisms Cardiolipin Tanned sheep cells

Cardiolipin Cardiolipin is extracted from animal tissues, such as beef hearts, and attached to carbon particles. In the presence of reagin, the particles will agglutinate.

Typing of RBCs with reagent antiserum represents which type of reaction? * Direct hemagglutination Passive hemagglutination Hemagglutination inhibition Reverse passive hemagglutination

Direct hemagglutination

Inactivation of sera for serological tests is performed for what purpose? * Destruction of complement Increasing sensitivity of test Removal of particulate matter Restoration of refrigerated sera to appropriate temperature for testing

Destruction of complement

A radiograph of a 1-year-old boy indicates the lack of a thymus. Complete blood count and flow cytometry confirm a below-normal lymphocyte count and a lack of T cells. Which of the following would most likely be the cause? * DiGeorge's syndrome Wiskott-Aldrich syndrome Bare lymphocyte syndrome Bruton's agammaglobulinemia

DiGeorge's syndrome DiGeorge syndrome is the most likely cause. In this syndrome the thymus fails to develop before birth. These patients also show a marked decrease in T cells.

Which of the following is the most common application of IMMUNOELECTROPHORESIS (IEP)? * Identification of the absence of a normal serum protein Structural abnormalities of proteins Screening for circulating immune complexes Diagnosis of monoclonal gammopathies

Diagnosis of monoclonal gammopathies

The process by which cells are capable of moving from the circulating blood to the tissues by squeezing through the wall of a blood vessel: * Chemotaxis Diapedesis Endosmosis Phagocytosis

Diapedesis

Protection from smallpox could be generated by the transfer of pustular material from cowpox lesion instead of the more hazardous smallpox lesion: * Edward Jenner Louis Pasteur Jules Bordet Robert Kaus

Edward Jenner

How are cytotoxic T cells (TC cells) and natural killer (NK) cells similar? * Require antibody to be present Effective against virally infected cells Recognize antigen in association with HLA class II markers Do not bind to infected cells

Effective against virally infected cells

A cell flow cytometry pattern belonging to a 3-year old patient showed the following: normal CD4+ T-cell count, normal CD19+ B-cell count, low CD8+ T-cell count. Which type of immunity would be affected? * Production of antibody Formation of plasma cells Elimination of virally infected cells Downregulation of the immune response

Elimination of virally infected cells

Patient serum is mixed with a suspension of guinea pig antigen. When the sample is then mixed with horse red blood cells, agglutination occurs. This is suggestive of an infection caused by: * Borrelia burgdorferi Hepatitis B virus Hepatitis C virus Epstein-Barr virus

Epstein-Barr virus INFECTIOUS MONONUCLEOSIS (EBV)The Davidsohn differential test can be used to detect heterophile antibodies produced during infectious mononucleosis. These antibodies are not adsorbed by guinea pig antigens. Therefore, the antibodies are available to agglutinate horse red blood cells.

Postzone causes false-negative reactions in antibody titers as a result of which of the following? Too much diluent added to test Excess antibody in test Excess antigen in test Incorrect diluent added to test

Excess antigen in test PROZONE Antibody excess, false negative Remedy: serum dilution POSTZONE Antigen excess, false negative Remedy: repeat test after a week to give time for antibody production

The type of graft rejection that occurs within minutes of a tissue transplant is ____________. * Acute Chronic Hyperacute Accelerated

Hyperacute The hyperacute tissue graft reject occurs within minutes to hours of a transplant and is typically associated with transplantation across ABO blood groups and anti-ABO antibodies.

Positive rheumatoid factor is generally associated with: * Anemia Azotemia Decreased ESR Hyperglobulinemia

Hyperglobulinemia Hypergammaglobulinemia such as polyclonal increase is associated with autoimmune disorders. Hypergammaglobulinemia such as monoclonal increase is associated with such disease states as multiple myeloma, lymphomas, etc.

Method of choice to detect T. gondii DNA in CSF: * EIA IFA FAMA PCR

PCR Currently, there are no useful serological procedures for diagnosing CNS infection in immunocompromised patients. These individuals often do not produce detectable levels of specific antibody against the parasite, and procedures to detect circulating antigen appear to lack sensitivity. PCR is, therefore, the method of choice to detect T. gondii DNA in CSF.

Prenatal congenital toxoplasmosis can be diagnosed by performing ______ on amniotic fluid to detect T. gondii DNA. * EIA IFA FAMA PCR

PCR Prenatal congenital toxoplasmosis can be diagnosed by performing polymerase chain reaction (PCR) technology on amniotic fluid to detect T. gondii DNA.

Rapid antigen detection for HISTIDINE-RICH PROTEIN II (HRP-II) is specific for: * Plasmodium falciparum Plasmodium malariae Plasmodium ovale Plasmodium vivax

Plasmodium falciparum HRP-II: Plasmodium falciparum pLDH AND ALDOLASE TESTS: All four Plasmodium spp.

HIV can infect all of the following cells except: * CD4+ subset of lymphocytes Macrophages Monocytes Polymorphonuclear leukocytes

Polymorphonuclear leukocytes In addition to T lymphocytes, macrophages, peripheral blood monocytes, and cells in the lymph nodes, skin, and other organs also express measurable amounts of CD4 and can be infected by HIV-1.

OX-19 and OX-2 refer to: * Strains of Proteus vulgaris Antigens of Rickettsia prowazeki Serotypes of Brucella abortus Antibodies to Salmonella typhi

Strains of Proteus vulgaris

Discovery of genetic principles underlying the generation of antibodies with different specificities: * Edward Jenner Ellie Metchnikoff Emil von Behring Susumu Tonegawa

Susumu Tonegawa

Recipient of the Nobel Prize for Physiology or Medicine in 1987, for his discovery of the genetic mechanism that produces ANTIBODY Georges Kohler and Cesar Milstein Gerald Edelman, Rodney Porter Susumu Tonegawa Rosalyn Yalow

Susumu Tonegawa

Which best characterizes the secondary response? * Equal amounts of IgM and IgG are produced There is an increase in IgM only There is a large increase in IgG but not IgM The lag phase is the same as in the primary response

There is a large increase in IgG but not IgM

Immunodeficiency with thrombocytopenia and eczema is often referred to as: * DiGeorge syndrome Bruton agammaglobulinemia Ataxia telangiectasia Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome Wiskott Aldrich syndrome is an X-linked recessive defect that exhibits immunodeficiency, eczema and thrombocytopenia.

What is the difference between nephelometry and turbidimetry? * a.) There is no difference between the two assays, only in name b.) Nephlometry is a newer example of turbidimetry c.) Nephlometry measures light transmitted through a solution, and turbidimetry measures light scattered in a solution d.) Nephlometry measures light scattered in a solution, and turbidimetry measures light transmitted through a solution

d.) Nephlometry measures light scattered in a solution, and turbidimetry measures light transmitted through a solution Nepholometry measures light at angles. The light source used for detection is placed at an angle from the detection device. Turbidometry detection devices are placed directly across from the light source and measures the intensity of the light as it passes through solution.